Cheap bike needed for trip

my mate from Australia is coming to visit and while i like him, its much better if we are on 2 separate bikes rather than one! (planning a trip across the uk and exploring Scotland)

so looking to spend about 1000 pounds, with mot and tax, hopefully at least a 600. Any type of bike will do as i will be selling it on once we get back anyway. But one thats not going to break down as soon as we leave London would be very helpful.

if anyone knows of anything that would be tops.